The invention relates to a facsimile machine of the type having two modes of operation. In the read mode a document is scanned and the image of the document is converted into an electrical signal which is representative of the image. This electrical signal can then be stored, transmitted via telephone or radio wave, or processed in another manner. In the second or write mode the facsimile machine receives an electrical signal, such as for instance from a telephone line, and converts the electrical signal into a fixed copy of the image represented by such electrical signal. Such facsimile, or fax, machines typically output the copy on a medium such as paper. It is highly desirable that one machine perform both functions by operating in both read and write modes. Typically prior art designs used separate mechanisms for the read mode in which a light source is directed upon the document and a signal is produced by the reflected light from the document as it is detected by a photoelectric detector which typically would be a photoelectric cell or similar sensor. Separate apparatus within the machine is used when an image signal is received by the fax machine to convert that image signal into an actual fixed copy. Prior art devices have included thermal paper, and photographic means. More recently fax machines have used a scanning laser head to place a photo image on a photo receptor device such as an electro-static drum copier. Such laser heads are relatively large and expensive, and in many instances require complicated scanning mirrors Both thermal printing heads and scanned laser printing heads are relatively slow and often require that the signal to be processed must be stored as it is received from a transmission line. Prior art fax machines have basically housed two separate systems, one being a copier, and one being a reading scanner device with little integration of the two separate functions.
Thin film electroluminescent line array emitters and printers using such are known. An example of this type of application is disclosed in U.S. Pat. No. 4,535,341 to Kun et al., one of the inventors of the present invention, and this patent being assigned to the assignee of the present invention. U.S. Pat. No. 4,535,341 is incorporated herein by reference. Other examples of thin film electroluminescent devices being used in printers are shown in U.S. Pat. Nos. 4,734,723 and 4,807,047.
It is an object of this invention to provide a facsimile machine which uses a thin film electroluminescent device to provide the photo-imaging source to a photoreceptor in the write mode, and also to provide the source for illuminating the paper when a scanning sensor is used in the reading mode.
It is also an object of this invention to provide a second source of light from a thin film electroluminescent device to be used during the read mode of a facsimile machine.